enable async backing client side for all runtimes

[librelois]

What does it do?

Enable async backing on the client side for moonriver and moonbeam.

Since Kusama enabled async backing on the relay config, parachain runtime require the inclusion of the parent parachain block head though the parachain system inherent, but moonkit include the parent head if and only if async backing is explicitly enabled client side, as a result collators with v0.37 can't produce blocks on moonriver as it panic at this line: https://github.com/moonbeam-foundation/polkadot-sdk/blob/moonbeam-polkadot-v1.3.0/cumulus/pallets/parachain-system/src/lib.rs#L1304

The only way to fix it is to enable async backing on the client side, it's fine to do that because moonkit with async backing enable still support old runtimes.

What important points reviewers should know?

Is there something left for follow-up PRs?

What alternative implementations were considered?

Are there relevant PRs or issues in other repositories (Substrate, Polkadot, Frontier, Cumulus)?

What value does it bring to the blockchain users?

[github-actions]

Coverage Report

@@                             Coverage Diff                             @@
##           perm-client-v0.37.1   enable-async-backing-client     +/-   ##
===========================================================================
  Coverage                73.06%                        73.06%   0.00%     
  Files                      228                           228             
  Lines                    69944                         69944             
===========================================================================
  Hits                     51103                         51103             
  Misses                   18841                         18841             

Files Changed	Coverage

Coverage generated Mon Apr 22 15:00:43 UTC 2024